Preheat the oven to 400°F. Line a 12 x 17-inch sheet pan with baking parchment.

In a medium bowl or measuring cup, whisk together the Buttermilk, Egg, and Baking Soda and set it aside while preparing the other ingredients.

Combine the Flour, Sugar, Baking Powder, and Salt in a large bowl. Mix the dry ingredients with a wire whisk, then cut in the Cold Butter with a pastry blender or 2 knives until the mixture looks like coarse meal. The largest pieces of Butter should be about the size of tiny peas. The butter should be suspended in tiny granules throughout the Flour, not rubbed into it to make a doughy mass. If any large chunks of Butter remain, break them up with your hands until they’re pea size, then stir in the Raisins and Caraway Seeds until they are evenly distributed.

Make a deep well in the center of the dry ingredients and pour the Buttermilk mixture into the well. Save the last bit of the Buttermilk mixture remaining in the bowl or cup for a glaze for later. Stir the wet and dry with a rubber spatula or a wooden spoon just until the dry ingredients look like a shaggy mass. This dough will be very wet but should be firm enough to hold its shape after the loaves have been formed. With floured hands, divide the dough evenly into two pieces. On a floured work surface, gently shape each piece into a rough-textured round about 5 inches in diameter. It should be more like a shaggy pile of dough than a smooth, compacted round ball. Be warned, your hands are going to be a gloppy mess. Place the rounds on the prepared sheet pan, leaving several inches between each loaf and around the edges of the pan to allow for spreading. Clean your hands. Then, using a floured dough scraper or a sharp knife, deeply score each round into 5 wedges, cutting all the way down to the pan. Try to cut the wedges as evenly as possible. Using a pastry brush, brush a little of the remaining buttermilk liquid onto the top of each loaf. Sprinkle the tops of the loaves with a little unbleached flour to give them a rustic look.

Bake the loaves in the center of the preheated oven for 20 minutes. Reduce the oven temperature to 375°F and rotate the pan from front to back. Continue baking for 15 to 20 more minutes, until the loaves are golden brown on both the top and bottom. A toothpick inserted in the center of a loaf should come out clean. Remove the loaves from the pans to cool on a wire rack. Serve slightly warm or at room temperature. Store any leftovers in an airtight container. They’re best if eaten within 2 days.